The invention is directed to a method and apparatus for handling electrical components and particularly for fetching and squaring electrical components and selectively testing electrical functioning of at least some of the components, in preparation for mounting of the components to a printed circuit board (PCB) automatedly by an insertion or surface mounting process.
Insertion, as the name implies, generally involves inserting the leads of a component through the holes of the circuit board and clinching protruding portions of the inserted leads to the underside of the board so as to hold the component in preparation for subsequent soldering of the leads to electrical tracks of the board.
Surface mounting generally involves surface mounting of miniature components, without the need for lead receiving holes at the mounting locations of the circuit board, as by using a dot of glue to hold the component in preparation for subsequent soldering of electrical connectors of the component to the electrical tracks. The thickness of these surface mounted components generally range from 0.018-0.062 inches, with width and length dimensions perpendicular to the thickness generally ranging from 0.040-0.250 inches. The electrical connectors of surface mountable components may comprise: conductive pads which are generally flush with the component body; hemispherical conductive balls; and/or conductive leads protruding from the body. The tips of the protruding conductive leads may extend past or be generally flush with the component body "mounting surface" which is adjacent and generally parallel to the circuit board top surface when mounted.
Input to a pick-up station may be in the form of taped components from reels or ammo packs and/or bulk components from vibratory feeders and flexible sticks. All of these types of inputs are presently used in prior art surface mounting machines in which pick and place heads are suspended above circuit boards and translatable in the X and Y coordinates of a horizontal plane in order to retrieve selected components from the inputs and mount them at selected positions on the circuit boards. However, such machines are physically limited in their capacity for board population by the limited numbers of input stations which are addressable by each pick and place head. Thus, the need exists for some manner of increasing the population capacities of such machines in a reliable and economical fashion.
Accordingly, it is an object of this invention to provide a method and apparatus for increasing the population capacities of surface mounting machines and the like while testing electrical functioning of selected components.
The invention comprises an extended input system by which additional component supply stations are located out of reach of the pick and place heads of a surface mounting machine and are selectively addressable by a supply shuttle which fetches individual components and delivers each component selectively to a test pocket or a utility pocket of a transfer assembly, from which the components are retrievable by a pick and place head of the machine. In a preferred embodiment, the transfer assembly provides a second shuttle on which the utility and test pockets are mounted for movement back and forth between the supply shuttle unload station to a pick-up station of the head, and the component testing occurs during transit of the transfer shuttle.